Question

A radio wave has a maximum magnetic field induction of ${10}^{-4}T$ on arrival at a receiving antenna. The maximum electric field intensity of such a wave is

• A. Zero
• B. $3\times {10}^4\raisebox{1ex}{$V$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$
• C. $5.8\times {10}^{-9}\raisebox{1ex}{$V$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$
• D. $3.3\times {10}^{-13}\raisebox{1ex}{$V$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$

Answer 1

The correct option is B

$3\times {10}^4\raisebox{1ex}{$V$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$

Step 1. Given data:

maximum magnetic field induction $\left(B_0\right)$ = ${10}^{-4}T$

Also, Speed of light $\left(c\right)$ = $3\times {10}^8\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

Step 2. Formula used:

maximum electric field intensity $\left(E_0\right)$ = Velocity of light $\left(c\right)$ X maximum magnetic field induction $\left(B_0\right)$

$E_0=c.B_0$

Step 3. Calculations:

Putting the values in the given formula, we get,

Thus, $$\begin{gathered} E_0=3\times {10}^8\times {10}^{-4} \\ =3\times {10}^{4}V{m}^{-1} \end{gathered}$$

Thus, the correct option is option B.